A special PTF (U86665.bff) provides POWER8 support on AIX 5.3 with the following limitations:

The LPAR must be at AIX 5.3 TL12 SP9 (latest 5.3 release).

The POWER8 LPAR will run in POWER6 compatibility mode and is limited to SMT2 mode. SMT2 mode results in some capacity loss compared to SMT4/SMT8 mode. IBM publishes SMT2 rPerf values that can be used to quantify Power8 SMT2 capacity.

mksysb – First perform an in place update to a supported (P5/P6/P7) AIX 5.3 TL12 SP9 LPAR with PTF U866665. Standard mksysb command can then be used to capture a P8 capable mksysb image. The mksysb image can then be used to install POEWR8 LPARs

NIM – An AIX 5.3 TL12 SP9 NIM environment must be updated to support POWER8. An AIX 5.3 TL12 SP9 NIM lpp_source must be updated to include PTF U866665. A NIM SPOT must then be created to utilize the updated lpp_source.

All POWER8 systems are supported with the following restrictions:

POWER8 system must be at 840 firmware level.

POWER8 LPAR must be served by a 2.2.4.10 VIOS.

Other restrictions:

Remote restart is not supported with POWER8 5.3 LPARs

POWER8 AIX 5.3 LPARs are not supported with a VIOS using Shared Storage Pools.

I tested this in my lab and it all worked as expected. I installed the PTF on an existing AIX 5.3 LPAR on a POWER7 750 and rebooted the partition.

[root@53gibbo]/ # lspv

hdisk0 00f603cdcd9ba6de rootvg active

[root@53gibbo]/ # oslevel -s

5300-12-09-1341

[root@53gibbo]/ # lsconf | more

System Model: IBM,8233-E8B

Machine Serial Number: 1003CDP

Processor Type: PowerPC_POWER7

Processor Implementation Mode: POWER 6

Processor Version: PV_6_Compat

Number Of Processors: 2

Processor Clock Speed: 3550 MHz

CPU Type: 64-bit

Kernel Type: 64-bit

LPAR Info: 3 53gibbo

Memory Size: 2048 MB

Good Memory Size: 2048 MB

Platform Firmware level: AL730_142

Firmware Version: IBM,AL730_142

[root@53gibbo]/tmp/cg/aix53p8 # inutoc .

[root@53gibbo]/tmp/cg/aix53p8 # ls -ltr

total 35808

-rw-r----- 1 root system 8994816 Feb 8 09:35 U866665.bff

-rw-r----- 1 root system 8994816 Feb 8 09:37 bos.mp64.5.3.12.10.U

-rw-r--r-- 1 root system 328592 Feb 8 09:37 .toc

[root@53gibbo]/tmp/cg/aix53p8 # update_all -d .

install_all_updates: Initializing system parameters.

install_all_updates: Log file is /var/adm/ras/install_all_updates.log

install_all_updates: Checking for updated install utilities on media.

install_all_updates: Processing media.

install_all_updates: Generating list of updatable installp filesets.

install_all_updates: The following filesets have been selected as updates

My POWER8 system was an S824 running the latest firmware (840_056), with VIOS running the latest code (2.2.4.10) and the latest HMC code (8.4).

p8vio1:/home/padmin# lsconf | head -20

System Model: IBM,8286-42A

Machine Serial Number: 214F55V

Processor Type: PowerPC_POWER8

Processor Implementation Mode: POWER 7

Processor Version: PV_7_Compat

Number Of Processors: 2

Processor Clock Speed: 3525 MHz

CPU Type: 64-bit

Kernel Type: 64-bit

LPAR Info: 101 82861_vio1

Memory Size: 18432 MB

Good Memory Size: 18432 MB

Platform Firmware level: SV840_056

Firmware Version: IBM,FW840.00 (SV840_056)

On my NIM master I created a new lppsource and SPOT for AIX 5.3 TL12 SP9 and included the required PTF U86665.

# lsnim -t spot | grep 53

spotAIX53TL12SP9 resources spot

# lsnim -t lpp_source | grep 53

AIX53TL12SP9 resources lpp_source

# nim -o showres spotAIX53TL12SP9 | grep bos.mp64

bos.mp64 5.3.12.10 C F Base Operating System 64-bit

# nim -o showres AIX53TL12SP9_P8 | grep bos.mp64

bos.mp64 5.3.11.2 I b usr,root

bos.mp64 5.3.12.9 S b usr

bos.mp64 5.3.12.10 S b usr

I took a mksysb on the 5.3 LPAR to my NIM master. I then used the mksysb to perform an NIM mksysb install (restore) to a new partition on the S824. This worked flawlessly. The partition was configured in POWER6 mode with SMT2 only.

[root@53gibbo]/ # oslevel -s

5300-12-09-1341

[root@53gibbo]/ # lsconf | head -10

System Model: IBM,8286-42A

Machine Serial Number: 214F55V

Processor Type: PowerPC_POWER8

Processor Implementation Mode: POWER 6

Processor Version: PV_6_Compat

Number Of Processors: 2

Processor Clock Speed: 3525 MHz

CPU Type: 64-bit

Kernel Type: 64-bit

LPAR Info: 2 53gibbo

Memory Size: 2048 MB

Good Memory Size: 2048 MB

Platform Firmware level: SV840_056

Firmware Version: IBM,FW840.00 (SV840_056)

Console Login: enable

Auto Restart: true

Full Core: false

[root@53gibbo]/ # smtctl

This system is SMT capable.

SMT is currently enabled.

SMT boot mode is not set.

SMT threads are bound to the same virtual processor.

proc0 has 2 SMT threads.

Bind processor 0 is bound with proc0

Bind processor 1 is bound with proc0

proc2 has 2 SMT threads.

Bind processor 2 is bound with proc2

Bind processor 3 is bound with proc2

[root@53gibbo]/ # lparstat -i

Node Name : 53gibbo

Partition Name : 53gibbo

Partition Number : 2

Type : Shared-SMT

Mode : Uncapped

Entitled Capacity : 0.20

Partition Group-ID : 32770

Shared Pool ID : 0

Online Virtual CPUs : 2

Maximum Virtual CPUs : 4

Minimum Virtual CPUs : 1

Online Memory : 2048 MB

Maximum Memory : 4096 MB

Minimum Memory : 1024 MB

Variable Capacity Weight : 128

Minimum Capacity : 0.10

Maximum Capacity : 4.00

Capacity Increment : 0.01

Maximum Physical CPUs in system : 24

Active Physical CPUs in system : 24

Active CPUs in Pool : 14

Shared Physical CPUs in system : 14

Maximum Capacity of Pool : 1400

Entitled Capacity of Pool : 1160

Unallocated Capacity : 0.00

Physical CPU Percentage : 10.00%

Unallocated Weight : 0

Desired Virtual CPUs : 2

Desired Memory : 2048 MB

Desired Variable Capacity Weight : 128

Desired Capacity : 0.20

The example above shows you how to migrate an AIX 5.3 system using NIM and mksysb. But you don’t have to do this, as LPM is fully supported. The migration effort for many customers is as easy as kicking off an LPM operation to move their (updated) AIX 5.3 partitions from their older Power servers to POWER8. Easy!

So I guess customers that still need to run AIX 5.3 on POWER8 now have an alternative to AIX 5.3 Versioned WPARs. But please keep in mind the performance and support considerations when making your decision.